#include<bits/stdc++.h>
using namespace std;

int main(){
	int n,k;
	cin >> n >> k;
	map<int,int> m;
	for(int i = 0;i < n;i++){
		int a;
		cin >> a;
		m[a]++;
	}
	vector<int> b;
	for(auto [key,value] : m){
		b.push_back(value);
	}
	sort(b.begin(),b.end());
	int s = (int)b.size() - 1;
	int ans = 0;
	while(k){
		k -= b[s];
		s--;
		ans++;
	}
	cout << ans << endl;
}